mPW1PW91 Calculated Relative Stabilities and Structures for the Conformers of 1,3-dimethoxy-p-tert-butylthiacalix[4]crown-5-ether

ABSTRACT. Molecular structures of the various conformers for the 1,3-dimethoxy- p-tert -butylthiacalix[4] crown-5-ether ( 3 ) were optimized by using DFT B3LYP/6 - 31 + G(d,p) and PW1PW91/6 - 31 + G(d,p) m(hybrid HF-DF) calculation methods. We have analyzed the energy differences and structures of eight in/ou t orientations ( cone_oo, cone_oi, pc_oo, pc_io, pc_oi, pc_ii, 13a_oo, 13a_io ) of two methoxy groups in three majorconformations (cone, partial-cone and 1,3-alternate). The 13a_oo (out-out orientation of the 1,3-alternate conformer) is calculated to be the most stable among eight different conformations of 3 , and in accord with theexperimental result . The ordering of relative stability resulted from the m PW1PW91/6 - 31 + G(d,p) calculatio nmethod is following: 13a_oo > 13a_io ∼ pc_io ∼ cone_oo > cone_oi ∼ pc_oo ∼ pc_oi > pc_ii . Keywords: DFT B3LYP, m PW1PW91, Conformer, Thiacalix[4]crown-5-ether 1,3- 디메톡시 - 티아캘릭스 [4] 크라운 -5- 에테르의 이형체들의 상대적인 안정성과 구조들에 대한 m PW1PW91 계산 연구